镍-不锈钢复合板轧制过程中界面的结合机制  

Interface Evolution During Rolling of Ni-clad Stainless Steel Plate

作　　者：范金辉[1] 李鹏飞 梁晓军[3] 梁建平 徐长征[3] 蒋力 叶祥熙 李志军 FAN Jinhui;LI Pengfei;LIANG Xiaojun;LIANG Jiangping;XU Changzheng;JIANG Li;YE Xiangxi;LI Zhijun(College of Mechanical Engineering,Donghua University,Shanghai 201620,China;Shanghai Institute of Applied Physics,Dalian National Laboratory for Clean Energy Chinese Academy of Sciences(CAS),Shanghai 201800,China;Baoshan Iron&Steel Co.,Ltd.,Shanghai 201900,China)

机构地区：[1]东华大学机械工程学院,上海201620 [2]上海应用物理研究所洁净能源创新院,上海201800 [3]宝山钢铁股份有限公司,上海201900

出　　处：《材料研究学报》2021年第7期493-500,共8页Chinese Journal of Materials Research

基　　金：上海市自然科学基金(18ZR1448000和19ZR1468200);上海扬帆计划(19YF1458300);国家自然科学基金(1671154、51601213、51671122和51971238);国家重点研发计划(2016YFB0700404);中国科学院青年创新促进协会(2019264);中国科学院战略先导专项(XD02004210&XDA21080100)。

摘　　要：采用轧制终止取样法对镍-不锈钢热轧复合板轧制过程中的界面成分、界面组织以及界面处的氧化物进行了表征,研究了轧制过程中界面的结合机制并根据热力学原理解释了高温下选择性内氧化的机理。将复合板坯加热至1200℃,保温120 min后进行轧制,分别在轧制3、5、7道次后中断轧制快速水冷,随后进行取样观察。结果表明,轧制3道次时终轧温度为1000℃左右,金属之间有近距离结合,微观组织有轻微的畸变,界面两侧的板材均为等轴晶粒,元素的扩散不甚明显;轧制至5道次时终轧温度为940℃左右,316H的晶粒被拉长而发生晶格畸变,界面附近出现明显的扩散行为;轧制到7道次时终轧温度为880℃,316H层出现大量拉长的畸变晶粒,界面处主要是轧碎的细晶组织,但Ni层的晶粒粗大,界面附近Ni、Fe和Cr元素充分扩散,微弱扩散的Mo元素在316H界面富集。镍-不锈钢复合板在轧制过程中界面的演化遵循三阶段理论和N.Bay理论,3道次到5道次间处于物理接触阶段、物理化学阶段,轧制7道次时物理化学阶段结束并开始扩散,即开始进入"体"相互阶段,主要元素在此阶段完成相互扩散。在高温低氧环境的轧制条件下,界面处生成Mn的氧化物,该氧化物因轧制而破碎并向基材挤压最终在界面附近成链状分布。Plate of Ni-clad 316H stainless steel was prepared via hot rolling process after pre-heating at 1200oC for 120 minutes,then concurrently the rolling process was interrupted after rolling for 3,5,and 7 passes respectively,while the relevant samples are taken and water-quenched for subsequent characterization in terms of the evolution of their interface-composition and-morphology,as well as the formed oxides there.Results show that until the 3rd rolling pass,the rolling plate temperature was about 1000°C,the two metals were closely bounded with equiaxed grains of slightly distorted microstructure on both sides of the interface and the inter-diffusion of elements for the two metals was not obvious;Until the 5th rolling pass,the plate temperature was about 940°C,the grains of 316H were elongated with significant lattice distortion,whereas,obvious inter-diffusion can be found near the interface;Until the 7th rolling pass,the plate temperature was about 880°C,large number of elongated and distorted grains were observed on the 316H steel side and a fine grain structure crushed by hot rolling distributed near the interface.The elements of Ni,Fe and Cr were fully inter-diffused near the interface,but the less motionable Mo enriched at the 316H side.The grains of Ni layer coarsened obviously.The interface evolution of Ni/stainless steel composite plate during the rolling process follows the so called three-stage theory and N.Bay's theory.The physical contact stage and the physical-chemical contact stage happened between the 3rd and 5th pass.Then the rolling from 5th to 7th pass was the final physical-chemical contact phase,whilst the inter-diffusion begins,that is,the"bulk"mutual phase begins.In the high-temperature and low-oxygen environment,the Mn oxides near the interface might form during the rolling process.The oxide was crushed and squeezed toward the substrate by the rolling force,therefore distributed in chains near the interface eventually.

关 键 词：材料表面与界面 镍-不锈钢复合板 微观结构 热轧复合 界面 

分 类 号：TG166.7[金属学及工艺—热处理]